Commercial limitations technologies

Catalytic combustion is an environmentally-driven, materials-limited technology with the potential to lower nitrogen oxide emissions from natural gas fired turbines consistently to levels well below 10 ppm. Catalytic combustion also has the potential to lower flammability at the lean limit and achieve stable combustion under conditions where lean premixed homogeneous combustion is not possible. Materials limitations [1,2] have impeded the development of commercially successful combustion catalysts, because no catalytic materials can tolerate for long the nearly adiabatic temperatures needed for gas turbine engines and most industrial heating applications. 

Despite all these advantages, two limitations remain, i.e., the continuous catalyst carry-over by the products that implies disposal, and the conversion level for olefins is highly dependent on their initial concentration in the feed. These commercial limitations have been greatly overcome through Difasol two-phase catalysis technology. 

In the following, each of these commercially important technologies will be discussed in some detail. In addition, a somewhat more limited description will be given of other process schemes which have less commercial importance today. The discussion will be limited to stand alone ammonia processes , i.e. processes producing ammonia without special considerations for production of other products. Simultaneous production of ammonia and other products, especially the simultaneous production of ammonia and a stoichiometric amount of carbon dioxide to convert all of the ammonia to urea, is treated in Sect. 6.5.4. 

Photopolymerization and Plasma Polymerization. The use of ultraviolet light alone (14) as well as the use of electrically excited plasmas or glow discharges to generate monomers capable of undergoing VDP have been explored. The products of these two processes, called plasma polymers, continue to receive considerable scientific attention. Interest in these approaches is enhanced by the fact that the feedstock material from which the monomer capable of VDP is generated is often inexpensive and readily available. In spite of these widespread scientific efforts, however, commercial use of the technologies is quite limited. 

Several more traditional materials have found specific though limited commercial apphcation as metal anodes. Examples are lead [7439-92-1] and ziac [7440-66-6] ia the electrogalvaniziag practice. Lead dioxide [1309-60-0] and manganese dioxide [1313-13-9] anode technologies have also been pursued. Two iadustrial electrolytic iadustries, aluminum [7429-90-5] and electric arc steel, stiU use graphite anodes. Heavy investment has been devoted to research and development to bring the advantages of DSA to these operations, but commercialization has not been achieved. 

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